Calculation of the Invasion of Drilling Fluid Resistivity Profiles With Borehole in Models of Carbonate Reservoirs With Varying Mineralogical

Abstract

It is well known the relationship between geological properties such as texture of the formations, and the petrophysical properties of reservoirs. This relationship is also dependent on the damage caused by the formation of drilling mud invasion, when the solid particles clog the porous medium. This invasion can modify the values of the profiles of the well, which can lead to erroneous esti-mates of oil saturation and reserves. This phenomenon is even more crucial in carbonates, where the porous sys-tem is complex because it can produce various types of porosity within the same array to intercrystalline, intergra-nular vuggy, fracture, etc. Moreover, the porosity also has a direct relationship with the mineralogical composition and may influence the responses of resistive profiles, which are commonly used to determine the diameter of invasion of mud into the reservoir. In this work, we simu-late the process of breaking into a mud-base oil in a re-servoir model of three layers, a salt, a carbonate and other shale. The methodology consisted of mineralogical variation in the layers, and calculate how this change affects the profiles of gamma ray and resistivity laterolog induction and calculating the diameter of invasion. The results show that under this condition, the profile laterolog presents more accurate results in calculating the invasion of the induction profile, given the lack of invasion caused by an oil-based mud compared to basic water and at its best record in the vicinity of well.